/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */
package ru.miit.elearning.servlets.pages;

import java.io.IOException;
import java.io.PrintWriter;
import java.util.List;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.hibernate.Session;
import ru.miit.elearning.hibernate.dao.CourseDAO;
import ru.miit.elearning.hibernate.dao.HibernateUtil;
import ru.miit.elearning.hibernate.dto.CurriculumLevel;

/**
 *
 * @author Cyclone
 */
public class CoursesServlet extends HttpServlet {

    /** 
     * Processes requests for both HTTP <code>GET</code> and <code>POST</code> methods.
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    protected void processRequest(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        response.setContentType("text/html;charset=UTF-8");
        PrintWriter out = response.getWriter();

        Session session = null;

        try {

            String sort = request.getParameter("sort");

            session = HibernateUtil.getSessionFactory().getCurrentSession();
            session.beginTransaction();
            CourseDAO courseDAO = new CourseDAO(session);

            List<CurriculumLevel> courseList = null;

            if (request.isUserInRole("admin")) {
                courseList = courseDAO.findAllCourses(sort);
            } else {
                int currentUserId = courseDAO.findUserIdByLogin(request.getRemoteUser());
                if (request.isUserInRole("tutor")) {
                    courseList = courseDAO.findCoursesByTutor(currentUserId, sort);
                    if (request.isUserInRole("student")) {
                        if (courseList != null) {
                            courseList.addAll(courseDAO.findCoursesByStudent(currentUserId, sort));
                        } else {
                            courseList = courseDAO.findCoursesByStudent(currentUserId, sort);
                        }
                    }
                } else {
                    if (request.isUserInRole("student")) {
                        courseList = courseDAO.findCoursesByStudent(currentUserId, sort);
                    }
                }
            }

            List<CurriculumLevel> directionList = courseDAO.findAllDirections();

            request.setAttribute("courseList", courseList);
            request.setAttribute("directionList", directionList);

            getServletContext().getRequestDispatcher("/courses.jsp").forward(request, response);
            session.getTransaction().commit();

        } catch (Exception e) {
            Logger.getLogger(CoursesServlet.class.getName()).log(Level.SEVERE, null, e);
            if (session != null && session.isOpen()) {
                session.getTransaction().rollback();
            }

            String message = "Ошибка запроса списка курсов";
            e.printStackTrace();

            getServletContext().setAttribute("message", message);
            getServletContext().getRequestDispatcher("/courses.jsp").forward(request, response);

        } finally {
            out.close();
            if (session != null && session.isConnected()) {
                session.close();
            }
        }
    }

    // <editor-fold defaultstate="collapsed" desc="HttpServlet methods. Click on the + sign on the left to edit the code.">
    /** 
     * Handles the HTTP <code>GET</code> method.
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        processRequest(request, response);
    }

    /** 
     * Handles the HTTP <code>POST</code> method.
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        processRequest(request, response);
    }

    /** 
     * Returns a short description of the servlet.
     * @return a String containing servlet description
     */
    @Override
    public String getServletInfo() {
        return "Short description";
    }// </editor-fold>
}
